The present invention relates to a new, flexible, heated wiper blade unit. More particularly, the invention relates to a wiper blade unit suitable for incorporation into new or existing windshield wiper assemblies.
Windshield wipers conventionally function by reciprocating a blade back and forth across a section of a windshield in front of the driver or passenger of a vehicle. Wipers can also be installed on the rear window of a vehicle, or on mirrors, headlights, or other lights. The wiper blade of the present invention is intended to be used in all or all of these situations.
In cold inclement weather, precipitation such as snow, sleet or rain may freeze and accumulate on surfaces to be cleared by the wiper. Ice may accumulate on the blade body and edge, lifting the blade from the windshield or other surface. As ice accumulates on the edge, the blade no longer efficiently clears precipitation from the windshield, and the windshield may frost over entirely. Alternatively, the blade may freeze in position at some point during its travel stroke.
Wiper blades are known in which resistive wire heating elements are embedded in the blade itself or positioned above the blade on the wiper assembly.
Devices which heat the metal assembly of the windshield wiper fail to efficiently heat the blade. The blade is primarily responsible for clearing accumulated precipitation from the windshield.
Wiper blades with incorporated resistive wire heating elements are often not sufficiently flexible to be used with windshields of any desired lateral or longitudinal curvature. Moreover, flexture of the blade during normal wiper operation tends to work harden wire heating elements, causing eventual failure of the elements and loss of heat production.
In order to make the blades more flexible, the prior art devices use a multitude of very thin wire-type heating elements, thus increasing the cost of production. Utilizing many very thin wires also causes extremely localized heating, placing undue thermal stress on the elastic material of the blade. Furthermore, many prior art devices have used expensive resistive materials such as NICHROME wires, and often require specialized wiper blade frames and/or wire arm assemblies.
It is therefore an object of the present invention to provide a flexible, heated wiper blade suitable for incorporation into new or existing windshield wiper assemblies.
Another object of the present invention is to provide a flexible wiper blade able to adapt to use on windshields having most any lateral or longitudinal curvature.
Another object of the present invention is to provide a heated wiper blade which is inexpensive to produce, is not fatigued by the repeated stresses of reciprocation, and is easy to replace and install.